The purpose of this project is to document and quantify the acoustic characteristics of the voice of patients with carcinoma of the larynx as they undergo irradiation for control of the tumor. Specifically, this project will obtain measurements of 1. fundamental frequency, 2. phonational range, 3. perturbation, 4. vocal intensity and, 5. acoustic spectrum of various speech utterances prior to treatment, weekly during treatment, and at regular intervals following the end of treatment. At the present time, 81 patients have commenced the recording sequence. Forty-seven of these have cancer involving the vocal cords whereas 34 have cancer near, but not involving, the larynx. Measurements of fundamental frequency and perturbation (jitter) are made in sustained vowels and sentences utilizing a pulse counting computer technique. The sound pressure level and 1/3 octave spectrum of sustained vowels and sentences are performed with a stepped 1/3 octave analyzer. The results of this project will document the acoustic changes in the voice as radiological treatment progresses. It is hoped that this technique will provide an additional prognostic indicator as to the success (or failure) of this treatment approach and may provide an earlier indication of tumor recurrence.